1. Field of the Invention
This invention relates to a metalic receptacle carrying cold liquified gas having a vacuum between a spaced jacket and the tank.
2. Description of the Prior Art
In common practice today, cryongenic fluids such as liquified natural gas or liquified nitrogen are transported cold in a tank. The tank has an outer shell or jacket. Traditionally these are carried horizontally and, therefore, the inner tank must not only have the strength to withstand the pressure of the fluid which it carries, but also it must have the strength to support itself between the supports. Commonly these tanks are transported by truck and are self supporting, i.e., a fifth-wheel rub plate is attached to one end and the tandum support attached to the other, the tank itself providing the sole support between the front and back.
In commercial practice today the fifth-wheel rub plate and tandum supports are both connected to the outer shell. The space between the outer shell and the inner shell is filled with insulation material and the air evacuated to form a vacuum insulation space between the outer shell or jacket and the inner structural shell. The outer shell is not thick.
Trouble is experienced in the cracking of the outer shell because of the structural strain placed thereon inasmuch as the structural supports at each end are attached to the outer shell. Once the outer shell is cracked, of course, the vacuum is spoiled and, therefore, the insulation is no longer effective.